Hi!
As I said ...I think the OS is slightly more powerful as it is a more modern design. I have run several of these "new" AX engines and they are as good as any other OS has been or better. ABC or ABN dose not matter when it comes to how long an engine will hold up or how much power it will deliver.
suitable props for both engines are 10x6 ,11x5 or even 11x6 ( if using the OS). Best prop brands are Graupner G Sonic or RAM. APC props are good too but not as good as those first mentioned.